1. Field of the Invention
This invention relates to a printing control system or a scanner control system in which a printer or a scanner is connected to a personal computer (a host computer), and the host computer controls the printer or the scanner to perform printing or scanning, respectively.
2. Description of the Related Art
Conventionally, a host computer (a personal computer) and a printer are connected to each other via an interface (Centronics or the like), and the printer sequentially processes printing data and printing instructions transmitted from the host computer to perform printing. The printing data and the printing instructions are formed by a printer-driver in the form of control codes peculiar to the printer, and are transmitted to the printer.
The printer analyzes control codes transmitted from the host computer, and, in the case of printing data, stores an amount of printing data which can be printed. Some control codes for printing data are provided in the form of rasters. Stored printing data is subjected to image processing or conversion processing so as to be reconstructed into image data which can be printed by a print head mounted in the printer, and the obtained image data is transmitted to the print head in order to perform printing. Control codes relate to processing for various controls for sheet feeding/discharging, feeding, and the like. Printing procedures in a Windows system provided by Microsoft Coropration will be described with reference to FIG. 31.
Correspondingly, a host computer (a personal computer) and a scanner are connected to each other via an interface (an SCSI (small computer system interface) or the like). The scanner sequentially processes scanning control codes transmitted from the host computer, and performs scanning by transmitting scanned image data to the host computer. The scanning control codes are control codes peculiar to the scanner, which are formed by scanner application software and are transmitted to the scanner. The scanner analyzes control codes transmitted from the host computer to perform a scanning operation and transmission of image data. Scanning control codes relate to processing for various controls for sheet feeding/discharging, feeding, and the like.
In the above-described conventional approach, the host computer forms a printing image according to printing instructions from application software, and forms control codes for printing data and printing instructions to be transmitted to the printer from the printing image. Since the host computer and the printer are completely independent of each other, the printer has many resources, such as a CPU (central processing unit), a ROM (read-only memory) for storing processing procedures, a RAM (random access memory) for storing data, and the like, in order to perform processing of analyzing control codes for printing, processing of developing an image, image processing, and the like. However, the performance of the host computer has been greatly improved compared with that of the printer, and in many cases, it is more advantageous to perform processing which has previously been performed in the printer in the host computer.
The present invention has been made in consideration of the above-described background.
It is an object of the present invention to provide a printing control system in a printer and a host computer in which resources conventionally incorporated in the printer are simplified to reduce the production cost by performing processing which has previously been processed by the printer by the host computer having a higher performance than the printer.
Conventionally, a host computer only forms and transmits control codes for scanning. Since the host computer and a scanner are completely independent of each other, the scanner has many resources, such as a CPU, a ROM for storing processing procedures, a RAM for storing data, and the like, in order to perform processing of analyzing control codes for scanning, control of scanning operations, image-ata processing, and the like. However, the performance of the host computer has been greatly improved compared with that of the scanner, and in many cases, it is more advantageous to perform processing which has previously been performed in the scanner in the host computer.
It is another object of the present invention to provide a scanner control system in a scanner and a host computer in which resources conventionally incorporated in the scanner are simplified to reduce the production cost by performing processing which has previously been processed by the scanner by the host computer having a higher performance than the scanner.
In the above-described host-computer-based printing system, in order to realize the control of the printer by the host computer, it is necessary to change Windows of Microsoft Corporation, a Windows printing sytem and a printer driver.
It is still another object of the present invention to provide a method relating to printer control in a printer and a host computer in which resources previously incorporated in the printer are simplified to reduce the production cost by performing processing previously performed by the printer by the host computer having a higher performance than the printer.
It is yet another object of the present invention to provide a printing control system in which it is unnecessary to change Windows, a Windows printing system and a printer driver, because conventional control codes from the printer driver are utilized as inputs.
In the conventional system, it is necessary for a host computer to form a printing image according to printing instructions from application software and to form control codes for printing data and printing commands to be transmitted to a printer from the printing image.
The printer has many resources, such as a CPU, a ROM for storing processing procedures, a RAM for storing data, and the like, in order to perform processing of analyzing commands for printing, processing of developing an image, image processing, and the like. However, the performance of the host computer has been greatly improved compared with that of the printer, and in many cases, it is more advantageous to perform processing which has previously been performed in the printer in the host computer.
It is yet a further object of the present invention to provide a printer control (time control) system in a printer and a host computer in which resources conventionally incorporated in the printer are simplified to reduce the production cost by performing processing which has previously been processed by the printer by the host computer having a higher performance than the printer.
According to one aspect, the present invention which achieves these objectives relates to a printing control system for controlling a printer from a host unit. The host unit includes control-code analysis means for analyzing control codes transmitted from a printer driver, control-I/O-command forming means for forming control I/O commands from the control codes, control-I/O-command transmission means for transmitting the control I/O commands to the printer, and control-I/O-command-execution instruction means for instructing execution of the control I/O commands transmitted from the control-I/O-command transmission means to the printer. The host unit causes the printer to execute printing using the control I/O commands formed by the control-I/O-command forming means and the control-I/O-command-execution instruction means.
According to another aspect, the present invention which achieves these objectives relates to a scanner control system for controlling a scanner from a host unit. The host unit includes control-code analysis means for analyzing control codes transmitted from scanner application software, control-I/O-command forming means for forming control I/O commands from the control codes, control-I/O-command transmission means for transmitting the control I/O commands to the scanner, and control-I/O-command-execution instruction means for instructing execution of the control I/O commands transmitted from the control-I/O-command transmission means to the scanner. The host unit causes the scanner to execute scanning using the control I/O commands formed by the control-I/O-command forming means and the control-I/O-command-execution instruction means.
According to still another aspect, the present invention which achieves these objectives relates to a printing control system for controlling a printer from a host unit. The system includes control-code analysis means for analyzing control codes, control-I/O-command forming means for forming control I/O commands from the control codes, control-I/O-command transmission means for transmitting the control I/O commands formed by the control-I/O-command forming means to the printer, control-I/O-command-execution instruction means for instructing execution of the control I/O commands transmitted from the control-I/O-command transmission means to the printer, and control-code transfer means for transferring control codes transmitted from a printer driver to the control-code analysis means.
According to yet another aspect, the present invention which-achieves these objectives relates to a printing control system for controlling a printer from a host unit. The system includes a printing control unit for controlling the printer. The printing control unit includes interface means for exchanging commands and data with the host unit, control-I/O-command holding means for holding control I/O commands transmitted from the host unit via the interface means, control-I/O-command control means for reading the control I/O commands held in the control-I/O-command holding means, and control-I/O-command execution means for controlling the printer according to the read control I/O commands. The printing control unit controls the printer using the control I/O command formed by the host unit.
According to yet a further aspect, the present invention which achieves these objectives relates to a printing control system for controlling a printer from a host unit in a real-time OS (operating system) environment. The system includes a printing control unit for controlling the printer. The printing control unit includes interface means for exchanging direct control I/O commands with the host unit, command control means for performing read/write access to a register at an arbitrary address in response to the direct control I/O commands from the host unit via the interface means, and command execution means for controlling the printer by performing read/write access to the arbitrary register. The host unit performs real-time control of the printer using the direct control I/O commands.
According to still a further aspect, the present invention which achieves these objectives relates to a printing. control system for controlling a printer from a host unit in which a printing control unit controls the printer using control I/O commands formed by the host unit. The printing control unit includes interface means for exchanging commands and data with the host unit, control-I/O-command holding means for holding control I/O commands transmitted from the host unit via the interface means, control-I/O-command control means for reading the control I/O commands held in the control-I/O-command holding means, and control-I/O-command execution means for controlling the printer according to the read control I/O commands. The control I/O commands transmitted from the control-I/O-command control means are configured in a form of the addresses of registers in the control-I/O-command execution means and data stored in the registers.
The foregoing and other objects, advantages and features of the present invention will become more apparent from the following description of the preferred embodiments taken in conjunction with the accompanying drawings.